Numerical simulation of the forbidden Bragg reflection spectra observed in ZnO

DOI: 10.1088/0953-8984/22/35/355404

Authors: E. N. Ovchinnikova (Moscow State University) , V. E. Dmitrienko (AV Shubnikov Institute of Crystallography) , A. P. Oreshko (Moscow State University) , G. Beutier (CEA, INAC) , S. P. Collins (Diamond Light Source)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Journal Of Physics: Condensed Matter , VOL 22 (35) , PAGES 355404

State: Published (Approved)
Published: September 2010

Abstract: Thermal motion induced (TMI) scattering is a unique probe of changes in electronic states with atomic displacements in crystals. We show that it provides a novel approach to extract atomic correlation functions. Using numerical calculations, we are able to reproduce the temperature-dependent energy spectrum of the 115 'forbidden' Bragg reflection in ZnO. Our previous experimental studies showed that the intensity growth of such reflections over a wide range of temperatures is accompanied by a dramatic change in the resonant spectral lineshape. This is the result of the interplay between the temperature-independent (TI) and temperature-dependent TMI contributions. Here, we confirm that the TI part of the resonant structure factor can be associated with the dipole-quadrupole contribution to the structure factor and show that the temperature-dependent part arises from the zinc and oxygen vibrations, which provide additional temperature-dependent dipole–dipole tensor components to the structure factor. By fitting the experimental data at various temperatures we have determined the temperature dependences of autocorrelation langux2(Zn)rang and correlation langux(O)ux(Zn)rang functions.

Subject Areas: Physics


Instruments: I16-Materials and Magnetism